H3c O

An alternative way of making estradiol is based on using androstenolon acetate (3-acetoxy-5-androsten-17-one) (28.1.18). Reduction of the keto-group in this molecule by hydrogen using a Raney nickel catalyst and subsequent acylation of the resulting hydroxyl group with benzoyl chloride forms a diester (28.1.19). This undergoes a number of transformations, in particular reduction of the double bond at C5 - C6 with hydrogen over a platinum catalyst, and then mild alkaline hydrolysis in methanol of the acetyl protecting group at C3, oxidation of the resulting hydroxyl group to a ketone using chromium (VI) oxide, and then the benzoyl protecting group of the hydroxyl at C17 is hydrolyzed by an aqueous base, giving the keto-alcohol (28.1.20). This compound undergoes bromination with molecular bromine, just as in the method described for making estrone, which results in the formation of a dibromide (28.1.21). This product undergoes dehydrobromination when heated in collidine, giving a dienone (28.1.22). When heated in tetraline to a temperature about 325 °C, methane molecule cleaves off the position 10 followed by aromatization of the ring A, and the desired estradiol (28.1.17) is formed [25,26]. Estradiol is also made in other ways [27,28].

Was this article helpful?

0 0
Reducing Blood Pressure Naturally

Reducing Blood Pressure Naturally

Do You Suffer From High Blood Pressure? Do You Feel Like This Silent Killer Might Be Stalking You? Have you been diagnosed or pre-hypertension and hypertension? Then JOIN THE CROWD Nearly 1 in 3 adults in the United States suffer from High Blood Pressure and only 1 in 3 adults are actually aware that they have it.

Get My Free Ebook


Post a comment